Well, are people on this drug less susceptible to the china flu? IOW, is it already working on them and preventing illness?
Can only give allegorical.
My uncle had the WuFlu. His wife never caught it even through she technically should have since she was the one in closest contact with him.
She does take this drug.
Then again my husband never caught it from me and he does not take this drug.
Make of that what you will.